Editing Asperger syndrome (section)

=== Restricted and repetitive interests and behavior ===

People with Asperger syndrome can display behavior, interests, and activities that are restricted and repetitive and are sometimes abnormally intense or focused. They may stick to inflexible routines, move in [[Stereotypy|stereotyped]] and repetitive ways, preoccupy themselves with parts of objects, or engage in compulsive behaviors like lining objects up to form patterns.<ref name="DSM-IV-TR 299.80" />

The pursuit of specific and narrow areas of interest is one of the most striking among possible features of AS.<ref name=McPart2006 /> Individuals with AS may collect volumes of detailed information on a relatively narrow topic such as weather data or star names without necessarily having a genuine understanding of the broader topic.<ref name=McPart2006 /><ref name=Klin /> For example, a child might memorize camera model numbers while caring little about photography.<ref name=McPart2006 /> This behavior is usually apparent by age five or six.<ref name=McPart2006 /> Although these [[Special interest (autism)|special interests]] may change from time to time, they typically become more unusual and narrowly focused and often dominate social interaction so much that the entire family may become immersed. Because narrow topics often capture the interest of children, this symptom may go unrecognized.<ref name=Klin />

Stereotyped and repetitive motor behaviors, called [[stimming]], are a core part of the diagnosis of AS and other ASDs.<ref>{{cite journal | vauthors = South M, Ozonoff S, McMahon WM | s2cid = 36078197 | title = Repetitive behavior profiles in Asperger syndrome and high-functioning autism | journal = Journal of Autism and Developmental Disorders | volume = 35 | issue = 2 | pages = 145–58 | date = April 2005 | pmid = 15909401 | doi = 10.1007/s10803-004-1992-8}}</ref> Stims are believed to be used for self-soothing and regulate [[Sensory processing disorder|sensory input]].<ref>{{Cite book |last=Foley |first=Valerie |url=https://books.google.com/books?id=FGO8S2RmckEC |title=The Autism Experience: International Perspectives on Autism Parenting |date=October 2011 |publisher=ReadHowYouWant.com |isbn=978-1-4587-9728-5 |language=en}}</ref> They include hand movements such as flapping or twisting, and complex whole-body movements.<ref name="DSM-IV-TR 299.80" /> These are typically repeated in longer bursts and look more voluntary or ritualistic than [[tic]]s, which are usually faster, less rhythmical, and less often symmetrical.<ref name=RapinTS>{{cite journal | vauthors = Rapin I | title = Autism spectrum disorders: relevance to Tourette syndrome | journal = Advances in Neurology | volume = 85 | pages = 89–101 | year = 2001 | pmid = 11530449}}</ref> Stimming may have a connection with tics, and studies have reported a consistent comorbidity between AS and [[Tourette syndrome]] in the range of 8–20%,<ref name=RapinTS/><ref>{{cite journal|vauthors=Steyaert JG, De la Marche W|year=2008|title=What's new in autism?|url=https://www.academia.edu/24262348|journal=Eur J Pediatr|volume=167|issue=10|pages=1091–101|doi=10.1007/s00431-008-0764-4|pmid=18597114|s2cid=11831418}}</ref><ref name="Mazzone">{{cite journal | vauthors = Mazzone L, Ruta L, Reale L | title = Psychiatric comorbidities in asperger syndrome and high functioning autism: diagnostic challenges | journal = Annals of General Psychiatry | volume = 11 | issue = 1 | pages = 16 | date = June 2012 | pmid = 22731684 | pmc = 3416662 | doi = 10.1186/1744-859X-11-16 | doi-access = free }}</ref><ref name="Gillberg&Billstedt2000"/> with one figure as high as 80% for tics of some kind or another,<ref name="Gillberg&Billstedt2000" /> for which several explanations have been put forward, including common genetic factors and [[dopamine]], [[glutamate]], or [[serotonin]] abnormalities.<ref>{{cite journal | vauthors = Zafeiriou DI, Ververi A, Vargiami E | title = Childhood autism and associated comorbidities | journal = Brain & Development | volume = 29 | issue = 5 | pages = 257–72 | date = June 2007 | pmid = 17084999 | doi = 10.1016/j.braindev.2006.09.003 | s2cid = 16386209}}</ref>

According to the Adult Asperger Assessment (AAA) diagnostic test, a lack of interest in fiction and a positive preference towards non-fiction is common among adults with AS.<ref name=ASAdulthood />